In vitro degradation of aflatoxin B-1 in groundnut (Arachis hypogea) meal by horse radish peroxidase

Finely powdered defatted groundnut meal was spiked with aflatoxin B-1 produ ced by Aspergillus flavus ATCC 15517. Commercial horseradish peroxidase (20 0 Umg(-1)) and partially purified peroxidase enzyme from freshly harvested radish roots having 20, 30 and 50 mu g(-1) of protein were made to act upon that toxin in vitro. The experiment resulted in 53, 28, 35 and 41%. conver sion, respectively. The optimum enzyme concentration occurred when 10 U of enzyme dissolved in 50 mM phosphate buffer at pH 6 was mixed homogeneously with 100 g of groundnut meal to react upon 1.4 mM AFB(1) at 20 degrees C an d normal pressure up to 24 h incubation period. Hydrogen pel oxide in 20 mM concentration was used as an oxidizing agent in all the reactions performe d. Moisture content of the reaction media was maintained at 12-15%. Calcium propionate 0.3 g/100 g of groundnut meal was used as fungistat. After enzy matic reaction, groundnut meal was tested for its toxicity on Bacillus mega terium cells. Toxicity tests resulted in 20, 30, 44 and 63% growth inhibiti on of bacilli when 200, 50 and 30 and 20 Umg(-1) enzyme treated groundnut m eal extracts were used for the reaction, respectively.